Agglomeration of biodiesel soot (BDS) in lubricating oil can increase the viscosity of the lubricating oil and result in engine wear. In order to enhance the dispersion of BDS and improve the lubricity of the lubricating oil with BDS

the influence of polyisobutylene succinimide dispersant (PIBSI) and calcium salt detergents (high alkaline calcium sulfonate (HACS)

alkyl calcium salicylate (ACS) and sulfuration calcium alkylphenol (SCA)) on the dispersion and tribological behavior of BDS in liquid paraffin (LP) was investigated by a viscosity method and a high frequency reciprocating test rig. The dispersion and tribological mechanism of BDS were carried out by X-ray photoelectron spectroscopy (XPS)

Zeta potentiostat

3D laser scanning microscopy

scanning electron microscopy and its affiliated energy-dispersive spectrometry. Results showed that the BDS that adsorbed (PIBSI+HACS) had the highest content of -OH

the least average particle size in LP

and the best dispersant performance

as compared with single addition. The wear volume of LP including 9% (PIBSI+HACS) and 5% BDS decreased from 7.73×105 μm3 to 5.42×105 μm3-a decline of 29.9%. The mechanisms analysis showed that (PIBSI+HACS) adsorbed on the surface of BDS through the hydrogen bonds and impeded the particle aggregation of BDS. It also dispersed the BDS particles in LP and inhibited their adsorption on the friction surfaces. Hence

(PIBSI+HACS) can improve the antiwear performance of LP with BDS.